Lock nut devices



United States Patent Office 3,153,195 Patented Dec. 29, 1964 LOCK NUT DEVICES William Henry Croswell, Columbus, hi`o,'assignor t0 Ranco Incorporated, Columbus, Ohio, a corporation ofl Ohlo ' Filed Feb. 15, 1962, Ser. No. 173,464

1 Claim. (Cl. 151-7) This invention relates to improvements in lock nut devices and more particularly to improved nut devices which cooperate with spring tension adjusting screws V rotatable to adjust the operating characteristics of control mechanisms, such as thermostatic or pressure operated switches and the like, and which devices prevent rotation and consequent shifting of the operating characteristics due to vibration, etc.

A common practice in control mechanism construction is to employ a tension spring between a movable arm and the frame of the mechanism With one end of the spring secured by an adjustable anchoring means in the form of a screw extending loosely through the arm or Other objects and advantages of nut devices embodying ythis invention will become apparent from the following detailed description of a preferred example thereof read in conjunction with the accompanying sheet of drawings forming a part of this specification, land in which:

FIG. 1 is'a longitudinal sectional view of a nut device embodying this invention as applied to the adjustable anchoring of a tension spring;

FIG. 2 is an end view of the nut device only and FIG. 3 is a sectional view of the nutV device taken substantially along line 3 3 of FIG. 2.

In `the form of the invention illustrated in the drawings, a self locking nut device, generally indicated at 10, is shown in association with a screw 11 to form an adjustable anchoring means between one end of a tension spring 12 and a stationary member such as a Wall 14'of a control mechanism (not shown). Nut device 10 comprises a of FIG. 1;

nut member 16 having an internally threaded central bore 17 and having external threads 19 adapted to belodged in the end convolutions 12a of coil spring 12.

Screw 11 has a threaded-shank 11a extending loosely through an opening 14a in Vwall 14'and threadedly received in threaded bore 17 as shown inV FIG. 1. Rotation of screw 11 in one direction or the other withrespectfto nut device 10 will cause the latter to move along shank 11a to increase or decrease the tension of spring 12. This above described anchoring arrangementfinds use in control mechanisms such as thermostatic switches and the due to snap acting characteristics of the controlmechanisms, it has beenl difficult to prevent undesired rotation of the screw and loss of adjustment while still permitting rotation of the screw byV use of a screw-driver or other hand tool to accomplish line adjustment of the spring tension. Y

It is a principal object of this invention toprovide an improved nut devicefor cooperation with a screw, which` Y nut device which offers substantially constant frictional resistance to rotation of a screw therein regardless of the direction of rotation of the screw.

Still another object of this invention is the provision of a nut device which offers substantially constant frictional resistance to rotation of a screw therein regardless of the position of the nut device along the length of the screw thread.

A more specific object of the invention is the provision of a locking device for a screw or -the like comprising a resilient thread gripping member or washer held against rotation and in-a manner'to permit it to flex in a direction axially of a central opening therethrough and Vwhich isfformed of material softer than the screw, the

opening through the washer being smaller than the dij ameter of the screwY so that by forcing the screw into the opening whileV rotating the same the washer is plastic material `such as Nylon or the like which is softer than the screw toV be used, is provided with a cenflexed and screw threads `are cut therein by the'screw 'l Vwhilethe washer is ilexed, whereby after the axial force on the screw is relieved the washerl tends to flex to its `as a screw-driver. a screw thread gripping resilient member which is shown in the form ofa washer 22 disposed in a cavity 23 formed like wherein the changes in tension in a spring such as 12 are utilized to varythe operating characteristics of the controlmechanism. One example of a mechanism using such fan anchoring arrangement is found in the previously mentioned U.S.'Patent No; 2,808,478. Such mechanisms are subjectpto shock, vibration,and the `like during opera-Ak tion thereof, sometimes resulting in inadvertent rotation V0f anchoring 'screw 11 and disturbance of the setting of .the operating characteristics of the switch or other mechanism; v

VThe nut device 10 of this invention comprises a self locking feature which frictionally resists undesired rotation of :a screw therein regardless of the position of theY nut device along the screw threadror of the direction of rotation of the screw, while still permitting line adjustment by rotation of the screw with a suitable tool such To this end nut device 10 comprises in one end of nut member 16. Cavity 23 is defined in part by an yannul-arwall `24 having an inner cylindrical is further defined by a frusto-conical sloping surface 27 leading from the inner edge of annular surface 26 to the open end of internally threaded bore 17.

. Resilient washer 22 is normally ldat and is disposed against the radially extending annular wall 26 and surrounded by cylindrical surface 25. Wall 24 is staked inwardly at a plurality of places as at 24a to securewasher 22 against rotation with respect to nut member 16. Resilient Washer 22, which Vis preferably formed of a suitable tral aperture 29 Vthe diameterof which is lessthan the major diameter oflinternallyV threaded bore 17 andprefer- `V ably no greater than the minimum diameter of the'internally threaded bore.

TFrusto-conical surface '27, which. slopes away from washer 22, permits deflection ofthe center portion of the washer when a screw is pressed axially thereagainst and vrotated into opening 29 so as to form its own thread 3 Y t therein. When the knutl device .10 is being assembled with a screw such as 11, the washer 22 is exed out of its normal plane and toward Wall 27 by airial pressure on the screw toward thetnut member untilfthe threads ofV tnesciew engage the rtlirdd ititrii ist the Bort. 17. Thereater,f\vashe'r 22 'teid's to t'rii lt its il'fr'i' `plane and 'exerts an axial forc ii ftli thds of th s'crvv in a diectio iitv-vardly t the Aniit 'rleiiib as well as constricting yfoi-cie n ,the srevi.V The -l 'stricting forc is the oibind it di nivvard' mf pnent'f force resiilfting from angular displacement of the washer as shown in FIG. 1, and from "radial .fci-

Y resistance efferati bythe axial force applied by vvz'tsherV 2i is independant tt-f, anti iii tiaititiiiftaaiiy frittioiial'neett Y;

resulting from radial compressin `of 'die `vi'l'asheir r'nai'erial as the `screvv formed threads therein. Y y y From the f oregoiii-g l`detailed description efaxlpkxiiut devi-e 10 eiitbtltiyiiig the prsent iiiveiitipait Vwinne ap'- piatiiitti that tha-ie has been piet/idea, tlitgibyn aV attinenstantially cbhsftant reisistal'ce'to relative rotation between the device and a streit/'assembled thieittwittiigy utilization of a resili-eiitly nexiblewasher which is axiailytlisplaed upon assembly 'of a sc'r'evv therewith, 'and which -iji'laslitgr thereafter provides axial, and rradial orce's gon the ,threads pf the screw which innipitjttatioii tlieittttii. VIt will alst be appreciated tlitthe lock nut/devices of 'this invention are particularly 'useful h applicationswheieinthe nut "vice is not 'drawn up tight agttiiis'tay 'toire .clamped thereby. t

Ythough the itiiiititiif his been deseaba fit1" etsiisiderable detail, and with rfrence "to aspediislr lpiting nut device embodying thenvention, it vviilbe `1`r`ljdei'- stood 'that the inveii'tien is iittt iiiiiittid, hieto, entrainer the invention includes all those adaptationgmodicatuions and uses as are reasonably embraced by the scope of the claim hereof. Having thus described my invention, I claim:

A self locking nut and screw device comprisingrin combination: y

(a) a. nut member having an internally threaded bore for receiving a screw and having an external thread means, Y, Y A (b) said nut meinbehaving a 'recess in one end thereof defined in part ybyv a cylindrical Wal-1 portion extendingaxially fromV alradially,v extending annular surface, saidV idially extending sif'ace being `s`ub stantilly prpiidiuli te the nut axis, and a misto,- t conical surface betvveenthe inner edge 'of said annular 'surface and the edgef said bore, said conical 'surface being inclined toward 'the other enti f 'said mit, 'Y t y Y j (c) a flat, iioii-ietauic resilient washer tiipjqsfejti against said annular surface and encircled by aid v cylindrical wall portion, l I .I .'(d) said cylindrical Wall having deformed portionsleh'- Vgagiii'g said resilient 'Washer to'secure said washer agaijns't Aro'ttitiiirelative to said nut member, 'said t washer 'having' a central Aopening rof smaller diameter than the 'major vdi'amieter of Said boi'r'e, said'screv'v being threadedly received in said opening ttbm said @e end and' t 1 (a) the eetttt'ai portitmpi said washer being resilienuy tutti angularly displaced nain a Irelatively flat Vttiit-4 dition to'w'rd said Yfrus'to-'cdrii'ca1 W'all by the lapplication "of force on said vv'a'she'r by-said sc're'w, said washer tetidiiig te returnl to said fiat conditi@ t, and exerting thereby a cnstric'tive component 'o'f force on said screw. 1 A

Retreices 'citen iii the rile of this `patent y UNITED STATES PATNT'S Y 1,367,151 Y A 1,9121 1,729,013 1929 27,222,469 j1, 940 2,400,343 .1,940 2,487,129 151,949 

